Primary conductor arrangement for a system for the inductive transmission of electrical energy

ABSTRACT

A primary conductor arrangement for a system for the inductive transmission of electrical energy, wherein the conductor arrangement includes an outgoing line and a return line that extend parallel to one another and can be connected to a current source in order to apply an electric current to the outgoing line and the return line. The conductor arrangement is divided into a plurality of adjacent sections, wherein each section contains an outgoing line and a return line as well as connection lines that connect the outgoing line and the return line. The sections are arranged relative to one another such that two adjacent sections overlap in a region near their connection line.

RELATED APPLICATION

This application is a continuation of International Patent Application No. PCT/EP03/01777, filed Feb. 21, 2003, the contents of which are here incorporated by reference in their entirety. Applicant claims the benefit of 35 USC Section 120.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention pertains to a primary conductor arrangement for a system for the inductive transmission of electrical energy.

2. Prior Art

Conductor arrangements for the contactless, inductive transmission of energy, in which a primary circuit is formed by two parallel lines that are spaced apart from one another by a certain distance, are generally known from the prior art, for example, according to DE 197 46 919 A1. A movable consumer that contains a secondary circuit, for example, a ground transport vehicle, can be displaced along such a primary conductor arrangement, wherein the aforementioned secondary circuit serves for the inductive reception of electrical energy from the magnetic field generated by the current-carrying primary circuit.

Known primary conductor arrangements are formed by a conductor loop that is installed along a line segment and connected to a current source. The conductor loop consequently comprises an outgoing line and a return line that are installed such that they extend parallel to one another and are spaced apart by a certain distance. The current source supplies the primary circuit thus formed with a current, with the current flowing in opposite directions in the outgoing line and the return line.

A sufficient energy density of the magnetic field generated by the primary circuit can only be achieved along the conductor arrangement with conventional current sources if the conductor arrangements have a limited range, i.e., a limited length of the outgoing line and the return line. However, an essentially arbitrary length of the conductor arrangement is required, particularly in the inductive energy supply of ground transport vehicles in order to provide the vehicle with an appropriate range. It would also be desirable to realize a largely homogenous field strength distribution along the primary circuit, i.e., a largely homogenous density of the magnetic field generated by the primary circuit.

SUMMARY OF THE INVENTION

Consequently, the invention is based on the objective of developing a primary conductor arrangement for the inductive transmission of electrical energy to a movable consumer enabling as large a range as possible for the consumer that is displaceable along the primary conductor arrangement, wherein a largely homogenous field-strength distribution should be generated along the primary conductor arrangement when a current is applied.

In a primary conductor arrangement according to the preamble of claim 1, this objective is attained with the features disclosed in the characterizing portion of claim 1. Advantageous embodiments of the invention are disclosed in the dependent claims.

The invention proposes to divide the conductor arrangement into a plurality of adjacent sections, wherein each section comprises an outgoing line and a return line as well as connection lines that connect the outgoing line and the return line, and wherein the sections are arranged relative to one another such that two successive sections overlap in the region near their connection line. The division of the primary circuit into several sections makes it possible to achieve a sufficiently high magnetic field density along the entire conductor arrangement since a current can be separately applied to each section by a current source. The overlap of the adjacent sections at their edges ensures a homogenous field-strength distribution in this transition area. A largely homogenous transition of the magnetic field-strength distribution from one section to the adjacent section not only ensures a uniform energy supply to the movable consumer along the line segment of the primary circuit, but is also particularly required if the magnetic field of the primary circuit is simultaneously utilized for tracking the movable consumer along the line segment.

The invention is described in greater detail below with reference to embodiments that are illustrated in the appended figures. The respective figures show:

a. FIG. 1, a schematic representation of a primary conductor arrangement;

b. FIG. 2, a detailed oblique representation of the overlapping region between two sections of the primary conductor arrangement shown in FIG. 1;

c. FIG. 3, a detailed oblique representation of the overlapping region between two sections of the primary conductor arrangement shown in FIG. 1, with two current supply points near the overlapping region;

d. FIG. 4, a detailed oblique representation of the overlapping region between two sections of the primary conductor arrangement shown in FIG. 1, with one current supply point near the overlapping region;

e. FIG. 5, an oblique representation of an intersection between the primary conductor arrangements according to FIG. 1, and

f. FIG. 6, a detailed oblique representation of an outgoing line and a return line of a section of the primary conductor arrangement shown in FIG. 1, with tuning capacitors respectively inserted into the outgoing line and the return line.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION

g. FIG. 1 schematically shows a primary circuit for a system for the inductive transmission of electrical energy that is formed by a primary conductor arrangement 1 according to the invention, said system being used for transmitting electrical energy to a consumer that can be displaced along the primary conductor arrangement 1. The primary conductor arrangement 1 is divided into a plurality of adjacent sections (A-H). Each of these sections (A-H) contains an outgoing line 2, a return line 3 and a connection line 5 that connects the outgoing line and the return line. The outgoing lines and the return lines of the sections (A-H) are respectively identified by the reference symbols 2X, 3X and 5X in FIG. 1, wherein X designates the respective conductor section (A-H).

The outgoing lines 2 and the return lines 3 are arranged parallel to one another in each section A-H, and the connection lines 5 form the transition between the outgoing line 2 and the return line 3. In this context, the term parallel arrangement of the outgoing lines and the return lines refers to the outgoing line and the return line 3 being spaced apart from one another by a constant distance. The respective lines may extend straight, as shown in sections A, C, E and G, or be bent in order to form a curve, as shown in sections B, D, F and H. The cables that form the primary conductor arrangement 1 are realized in the form of bunched conductors. Each section (A-H) of the primary conductor arrangement 1 contains a current source 4 for applying a current to the conductor loop of the respective section that is formed by the outgoing line 2, the connection line 5 and the return line 3. In the section identified by the reference symbol A in FIG. 1, the outgoing line 2A is connected to a current source 4A via supply lines 8A and 9A. The supply lines 8A, 9A extend approximately perpendicular to the outgoing line 2A.

The other sections B-H are analogously provided with one respective current source 4B, 4C, . . . 4H, wherein the current sources are connected to either the outgoing line 2 or the return line 3.

One respective adjacent section is situated on either side of each section of the conductor arrangement, such that it forms an extension of the outgoing line 2 and the return line 3, respectively, as illustrated in FIG. 1. For example, the section B is situated to the right, and the section H is situated to the left, of section A. Adjacent sections are arranged relative to one another such that they overlap in an overlapping region 7 near the respective connection line 5. This overlap is realized such that the outgoing line 2X of one section extends directly above and closely adjacent to the corresponding outgoing line 2X+1 of the adjacent section in the overlapping region 7. This applies analogously to the return lines 3 of adjacent sections within the overlapping region 7.

FIG. 2 shows a detailed representation of the overlapping region 7 between two adjacent sections A, B. FIG. 2 indicates that the length of the overlapping region 7 in the longitudinal direction of the outgoing line and return line approximately corresponds to the length of the respective connection lines 5A and 5B, which are curved in a semicircular shape. This is why the conductor arrangement has the shape of a circular winding if it is viewed from the top. However, the overlapping region 7 may also be made larger, for example, approximately twice as large as the length of the connection lines.

FIG. 3 also shows the overlapping region 7 between two adjacent sections A and B, wherein current supply points for applying a current to the outgoing lines 2A and 2B of the respective sections A and B are provided in the vicinity of the overlapping region 7. These current supply points are respectively formed by supply lines 8B, 9B and 8A, 9A that branch off the respective outgoing lines 2B and 2A and are connected to the current source 4. The respective supply lines 8B, 9B and 8A, 9A extend approximately perpendicular to the respective outgoing lines 2B and 2A. The supply lines 8, 9 are installed closely adjacent to one another in plastic tubes 10. Alternatively to the plastic tubes 10, the supply lines 8 and 9 may also be installed closely adjacent to one another by means of cable ties. Due to the perpendicular alignment of the supply lines 8, 9 relative to the outgoing line 2, undesirable magnetic interference fields are not generated by said supply lines in the longitudinal direction of the outgoing line or return line. The angled or bent section that respectively forms the transition from the supply lines 8, 9 to the corresponding outgoing line 2 and return line 3 is made as short as possible and bent in the smallest radius possible without producing kinks in the cable. In another embodiment that is not illustrated in the figures, the two supply lines 8, 9 are installed such that they lie on top of one another in the bent region. A largely homogenous field distribution of the magnetic field generated by the current-conducting conductor arrangement is achieved in this fashion in the vicinity of the current supply points.

FIG. 4 shows an embodiment in which the current supply point of a section B is arranged near the overlapping region 7. The supply point of the adjacent section A, in contrast, is spaced apart from the overlapping region 7 by a larger distance, and consequently is no longer visible in the detail according to FIG. 4.

FIG. 5 shows an intersection of two primary conductor arrangements 1 a and 1 b. According to this figure, the outgoing line and the return line of two sections B_(1b) and B_(1a) of the two primary conductor arrangements 1 a and 1 b intersect in an intersecting region 11. The regions 7 overlapping with the respective adjacent sections A_(1b) and A_(1a) of the corresponding primary conductor arrangements 1 a and 1 b preferably lie a sufficient distance from the intersecting region 11. In this context, the term sufficient distance refers to at least the electrically effective length of the secondary winding of the energy receiving unit of the movable consumer.

In order to make it possible to tune the primary conductor arrangement and the energy receiving unit of the movable consumer that carries the secondary winding to resonance, at least one tunable capacitor 12 is provided in each section (A-H) of the primary conductor arrangement. FIG. 6 shows a detailed representation of one section of a primary conductor arrangement. One respective tunable capacitor 12 is inserted into the outgoing line 2 as well as into the return line 3 via branch lines 13, 14; 15, 16. Relative to the branch lines 15, 16 of the return line 3, the branch lines 13, 14 of the outgoing line 2 are arranged offset relative to one another by a certain distance along the primary conductor arrangement, said distance being at least as large as or larger than the electrically effective length of the energy receiving unit of the movable consumer. 

1. A primary conductor arrangement for a system for the inductive transmission of electrical energy, wherein the conductor arrangement comprises an outgoing line and a return line that extend parallel to one another and can be connected to a current source in order to apply an electric current to the outgoing line and the return line, characterized in that the conductor arrangement is divided into a plurality of adjacent sections, wherein each section contains an outgoing line and a return line as well as connection lines that connect the outgoing line and the return line, and in that the sections are arranged relative to one another such that two adjacent sections overlap in a region near their connection line.
 2. The primary conductor arrangement according to claim 1, characterized in that the length L of the overlapping region approximately corresponds to the length of the connection lines.
 3. The primary conductor arrangement according to claim 1, characterized in that the successive sections overlap in the longitudinal direction of the primary conductor arrangement.
 4. The primary conductor arrangement according to claim 1, characterized in that the outgoing line and the return line of one section lie on top of the outgoing line and the return line of the adjacent section in the overlapping region.
 5. The primary conductor arrangement according to claim 1, characterized in that the free ends of one of the outgoing line and the return line of each section are connected to a pair of supply lines for connecting the one of the outgoing line and the return line to a current source, wherein the supply lines extend approximately perpendicular to the one of the outgoing line and return line.
 6. The primary conductor arrangement according to claim 5, characterized in that the two supply lines of one section that form a pair respectively contain a straight region and an adjacent curved region, with the straight regions extending parallel to and closely adjacent to one another, and with the curved regions of the two supply lines crossing on top of one another.
 7. A system for the inductive transmission of electrical energy, with a primary conductor arrangement according to claim 1 for the transmission of electrical energy to a consumer that can be displaced along the primary conductor arrangement, wherein the consumer contains an energy receiving unit for the inductive reception of electrical energy from the magnetic field generated by the primary conductor arrangement.
 8. The system according to claim 7, characterized in that each section of the primary conductor arrangement is supplied with an electric current by a separate current source.
 9. The system according to claim 7 characterized by two intersecting primary conductor arrangements, each comprising a primary conductor arrangement for a system for the inductive transmission of electrical energy, wherein the conductor arrangement comprises an outgoing line and a return line that extend parallel to one another and can be connected to a current source in order to apply an electric current to the outgoing line and the return line, characterized in that the conductor arrangement is divided into a plurality of adjacent sections, wherein each section contains an outgoing line and a return line as well as connection lines that connect the outgoing line and the return line, and in that the sections are arranged relative to one another such that two adjacent sections overlap in a region near their connection line, and wherein the overlapping regions of the sections of each conductor arrangement lie outside an intersecting region.
 10. The system according to claim 7, characterized in that resonance tuning is realized by respectively inserting at least one tunable capacitor into the outgoing line and the return line of each section of the conductor arrangement, wherein said tunable capacitor is connected to one of the outgoing line and the return line by means of branch lines, and wherein the branch lines of the outgoing line and the branch lines of the return line are arranged offset relative to one another by a distance A that is at least as large as the electrically effective length of the energy receiving unit of the consumer in the longitudinal direction as referred to the primary conductor arrangement. 